John M. Hayes was born in Seattle, Washington, on September 6, 1940, and spent his childhood mainly in the American Northwest. He attended Iowa State University in Ames where he earned a bachelor of science degree in geology in 1962. He obtained his Ph.D. in chemistry at the Massachusetts Institute of Technology, Cambridge, in 1966. He was briefly a postdoctoral scholar at the University of Chicago, Illinois, at the Enrico Fermi Institute in 1966. He served in the U.S. Army from 1967-1968 in the Chemical Evolution Branch at the NASA Ames Research Center in California. After that, he held a one-year NATO-National Science Foundation postdoctoral fellowship in organic geochemistry at the University of Bristol, England, in 1969. He joined the faculty at Indiana University, Bloomington, in 1970, where he was named Distinguished Professor of biogeochemistry in 1990 and served as chairperson of the department from 1994 to 1996. In 1996, Hayes accepted the position of senior scientist and director of the National Ocean Sciences Accelerator Mass Spectrometry Facility at the Woods Hole Oceanographic Institution of the Massachusetts Institute of Technology. Hayes was also a professor of practice at Harvard University, Massachusetts, beginning in 1997. He was a visiting scientist at the University of California at Los Angeles (1979-1980), and Australia Bureau of Mineral Resources, Geology and Geophysics (1988). In 1962, John Hayes married Janice Maria Boeke. They had three children. John Hayes authored 170 articles in international journals, four chapters in professional volumes, and two textbooks in the fields of mass spectrometry, organic cosmochemistry, microbial biochemistry, isotopic and organic geochemistry, and chemical oceanography. He received numerous honors and awards for his research. Hayes won an Eastman Prize as a graduate student at the Massachusetts Institute of Technology in 1962-1964. In 1987-88 he was a Fellow of the John Simon Guggenheim Memorial Foundation. He was a Bennett lecturer at the University of Leicester in 1990, an Ingersoll lecturer with the Geochemical Society in 1994, and a Krumbein lecturer at the University of Chicago in 1994. In 1997, he was awarded the Harold C. Urey Medal of the European Association for Geochemistry. In 1998, he was awarded the Treibs Medal of the Geochemical Society and elected to membership in the National Academy of Sciences and the American Academy of Arts and Sciences. Professor Hayes passed away at his home in Berkeley, California, on February 3, 2017 at the age of 77.